The Peppered Moth

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Peppered Moth Simulation Lab Objectives: Describe the importance of coloration in avoiding predation Relate environmental change to changes in organisms Explain how natural selection causes populations to change

Materials: Sheet of black paper Sheet of newspaper Tweezers Crayons Clock/Timer 30 Newspaper moths 30 black moths

Purpose: In this lab you will simulate how predators locate their prey in different environments. You will also analyze how color affects an organism’s ability to survive in certain environments.

The Peppered Moth: When a population adapts in response to pollution levels it is called Industrial Melanism. Rapid industrial melanism occurred in populations of peppered moths in the area of Manchester, England between 1845 and 1890. Before the industrial revolution, the trunks of the tress in the forests around Manchester were light grayish-green because of the presence of lichens. Most of the peppered moths in the area were light colored with dark spots (like the one in the picture on the right!). As the industrial revolution progressed the tree trunks became covered with soot and grime and turned dark. Over the forty-five year period more and more dark moths (like the one in the picture on the left!) were seen and fewer light colored moths were observed.

Procedure: 1. Get into partners. Determine who will be the ‘predator’ first and who will be the ‘scientist’. 2. Place a sheet of black paper on the table and have the ‘scientist’ spread 30 black moths and 30 newspaper moths over the surface when the ‘predator’ isn’t looking. 3. The ‘predator’ will then use the tweezers to catch as many moths as they can in 15 seconds. 4. This trail will be repeated with the combinations listed in the observation table. They are: newspaper moths on newspaper, black moths on newspaper, newspaper moths on black paper, and black moths on black paper. 5. The scientist records the number of moths the predator caught in their partners observation chart. 6. Answer the post lab questions – can do this as a class!

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Observation Chart: Trail

Background

Starting Population Newspaper Black

Black

30

30

Black

0

30

Newspaper

30

30

Newspaper

30

0

Number Picked Up Newspaper Black

1 2 3 4 Use your observations to answer the following questions!

Analysis: 1. What did the experiment show about how prey animals are selected by predators?

2. What moth coloration is the best adaptation for a dark background? How do you know this?

3. What would you expect the next generation of moths to look like after trial 1? After trial 3? Why?

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4. How does this lab simulation model natural selection?

5. Use the following data and make a line graph on the grid paper provided. Remember to plot time on the X-axis and number of moths captured on the Y-axis. There will be two lines on your graph. Use crayons to color in your lines, make sure you include labels for the axis, a legend and a title. Year 2 3 4 5 6 7 8 9 10

# Light Moths Captured 549 432 399 267 223 189 136 92 51

# Dark Moths Captured 116 194 233 291 345 413 498 548 596

6. What does your graph show? How do you know this?

7. Think about current events, global issues, or things you have seen in nature around you. Now come up with a situation where this type of selection might occur? Briefly explain your idea and do a quick sketch showing what the adaptations look like.

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